jburkardt

TETRAHEDRON_PROPERTIES\ Compute Properties of a Tetrahedron {#tetrahedron_properties-compute-properties-of-a-tetrahedron align=”center”} ===================================

TETRAHEDRON_PROPERTIES is a C++ program which computes properties, including the centroid, circumsphere, dihedral angles, edge lengths, face angles, face areas, insphere, quality, solid angles, and volume, of a tetrahedron in 3D.

Usage: {#usage align=”center”}

tetrahedron_properties filename

where filename contains the vertex coordinates.

Licensing: {#licensing align=”center”}

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages: {#languages align=”center”}

TETRAHEDRON_PROPERTIES is available in a C++ version and a FORTRAN77 version and a FORTRAN90 version and a MATLAB version.

GEOMETRY, a C++ library which performs geometric calculations in 2, 3 and N dimensional space.

HYPERSPHERE_PROPERTIES, a C++ library which carries out various operations for an M-dimensional hypersphere, including converting between Cartesian and spherical coordinates, stereographic projection, sampling the surface of the sphere, and computing the surface area and volume.

POLYGON_PROPERTIES, a C++ library which computes properties of an arbitrary polygon in the plane, defined by a sequence of vertices, including interior angles, area, centroid, containment of a point, convexity, diameter, distance to a point, inradius, lattice area, nearest point in set, outradius, uniform sampling.

TETRAHEDRONS, a dataset directory which contains examples of tetrahedrons;

TRIANGLE_PROPERTIES, a C++ program which computes properties of a triangle whose vertex coordinates are read from a file.

Source Code: {#source-code align=”center”}

tetrahedron_properties.cpp, the source code.

Examples and Tests: {#examples-and-tests align=”center”}

tet_cap.txt, a “cap” tetrahedron.
tet_cap_output.txt, the output file.
tet_equilateral.txt, an equilateral tetrahedron.
tet_equilateral_output.txt, the output file.
tet_needle.txt, a “needle” tetrahedron.
tet_needle_output.txt, the output file.
tet_right.txt, a right tetrahedron.
tet_right_output.txt, the output file.
tet_sliver.txt, a “sliver” tetrahedron.
tet_sliver_output.txt, the output file.
tet_spindle.txt, a “spindle” tetrahedron.
tet_spindle_output.txt, the output file.
tet_wedge.txt, a “wedge” tetrahedron.
tet_wedge_output.txt, the output file.

List of Routines: {#list-of-routines align=”center”}

MAIN is the main program for TETRAHEDRON_PROPERTIES.
ARC_COSINE computes the arc cosine function, with argument truncation.
CH_CAP capitalizes a single character.
CH_EQI is true if two characters are equal, disregarding case.
CH_TO_DIGIT returns the integer value of a base 10 digit.
DTABLE_DATA_READ reads the data from a DTABLE file.
DTABLE_HEADER_READ reads the header from a DTABLE file.
FILE_COLUMN_COUNT counts the columns in the first line of a file.
FILE_ROW_COUNT counts the number of row records in a file.
I4_MAX returns the maximum of two I4’s.
I4_MIN returns the minimum of two I4’s.
R8_ABS returns the absolute value of an R8.
R8_HUGE returns a “huge” R8.
R8_MAX returns the maximum of two R8’s.
R8_MIN returns the minimum of two R8’s.
R8_SWAP switches two R8’s.
R8MAT_DET_4D computes the determinant of a 4 by 4 R8MAT.
R8MAT_SOLVE uses Gauss-Jordan elimination to solve an N by N linear system.
R8MAT_TRANSPOSE_PRINT prints an R8MAT, transposed.
R8MAT_TRANSPOSE_PRINT_SOME prints some of an R8MAT, transposed.
R8VEC_ANGLE_3D computes the angle between two vectors in 3D.
R8VEC_CROSS_3D computes the cross product of two R8VEC’s in 3D.
R8VEC_DOT computes the dot product of a pair of R8VEC’s in ND.
R8VEC_LENGTH returns the Euclidean length of an R8VEC.
R8VEC_MAX returns the value of the maximum element in an R8VEC.
R8VEC_PRINT prints an R8VEC.
R8VEC_ZERO zeroes an R8VEC.
S_LEN_TRIM returns the length of a string to the last nonblank.
S_TO_R8 reads an R8 from a string.
S_TO_R8VEC reads an R8VEC from a string.
S_WORD_COUNT counts the number of “words” in a string.
TETRAHEDRON_CENTROID_3D computes the centroid of a tetrahedron in 3D.
TETRAHEDRON_CIRCUMSPHERE_3D computes the circumsphere of a tetrahedron in 3D.
TETRAHEDRON_DIHEDRAL_ANGLES_3D computes dihedral angles of a tetrahedron.
TETRAHEDRON_EDGE_LENGTH_3D returns edge lengths of a tetrahedron in 3D.
TETRAHEDRON_FACE_ANGLES_3D returns the 12 face angles of a tetrahedron 3D.
TETRAHEDRON_FACE_AREAS_3D returns the 4 face areas of a tetrahedron 3D.
TETRAHEDRON_INSPHERE_3D finds the insphere of a tetrahedron in 3D.
TETRAHEDRON_QUALITY1_3D: “quality” of a tetrahedron in 3D.
TETRAHEDRON_QUALITY2_3D: “quality” of a tetrahedron in 3D.
TETRAHEDRON_QUALITY3_3D computes the mean ratio of a tetrahedron.
TETRAHEDRON_QUALITY4_3D computes the minimum solid angle of a tetrahedron.
TETRAHEDRON_SOLID_ANGLES_3D computes solid angles of a tetrahedron.
TETRAHEDRON_VOLUME_3D computes the volume of a tetrahedron in 3D.
TIMESTAMP prints the current YMDHMS date as a time stamp.
TRIANGLE_ANGLES_3D computes the angles of a triangle in 3D.
TRIANGLE_AREA_3D computes the area of a triangle in 3D.

You can go up one level to the C++ source codes.

Last revised on 09 July 2009.